电焊机2025，Vol.55Issue(7)：64-72,9.DOI:10.7512/j.issn.1001-2303.2025.07.06
P700L/SAPH440-B异种高强钢焊接接头组织与性能分析
Microstructure and Properties Analysis of Welded Joint of P700L/SAPH440-B Dissimilar High Strength Steel
摘要
Abstract
In this experiment,P700L/SAPH440-B dissimilar high-strength steel was used for welding with ER69-G wire and carbon dioxide-shielded welding.Under the condition of welding line energy of 7 kJ/cm,the welded joint has excellent me-chanical properties.An optical microscope(OM)was used to observe and analyze the microstructure of the weld and heat-affected zone(HAZ)on both sides,scanning electron microscope(SEM)and energy dispersive spectrometer(EDS)were used to observe and analyze the inclusion of acicular ferrite induced in weld,and impact testing machine,universal testing machine and Vickers hardness tester were used to detect the mechanical properties of welded joints.It is concluded that the microstructure of the weld area is acicular ferrite and bainite,in which acicular ferrite occupies most of the area.The micro-structure of the HAZ on the SAPH440-B side and P700L side is mainly granular bainite and lath bainite,while the granular bainite on the P700L side is more coarse.The inclusions inducing acicular ferrite nuclei in the weld are mainly oxides of Ti,Al,and Si,and a certain Mn-poor zone is generated around the inclusions.The average tensile strength of the welded joint is 536 MPa,which is higher than the average tensile strength of the two kinds of steel 517 MPa.There is a softening phenom-enon in the HAZ on both sides of the welded joint,and the softening phenomenon in the HAZ on the P700L side is very ob-vious and is the lowest hardness value of the whole welded joint.In the characteristic region of the welded joint,the average impact energy of the HAZ on the P700L side is the highest,reaching 88J.The average impact energy of the whole character-istic region of the welded joint is more than 70%of the base material,and the impact toughness is good.There were no cracks in the surface bend and back bend of the welded joint.关键词
高强度大梁钢/CO2气体保护焊/显微组织/力学性能Key words
high strength large beam steel/CO2 gas shielded welding/microstructure/mechanical property分类
矿业与冶金引用本文复制引用
章哲,张明,张朋彦..P700L/SAPH440-B异种高强钢焊接接头组织与性能分析[J].电焊机,2025,55(7):64-72,9.基金项目
国家自然科学基金(52274375) （52274375）
安徽省重点研发计划(202104a05020020) （202104a05020020）
